Precipitation#
The charts below show precipitation trends in the watersheds. You will see plots with annual, monthly, and daily precipitation amounts. Atmospheric river events are also highlighted. The reference station for these plots is the Lower Capilano Fire Weather station, on the east side of the Capilano Reservoir. Precipitation amounts tend to be greater further to the north.
The map below shows the total annual precipitation for a number of weather stations in the region. You can click on the stations to see the total precipitation for that site.
The chart below shows annual precipitation totals at the Vancouver Airport from 1937 to 2024. This past year was much wetter than the past several years. It was the 8th wettest year since records began.
The chart below shows daily precipitation amounts at the Lower Capilano Fire Weather Station. On October 19, 216 mm of rain fell during an atmospheric river event.
The next plot below breaks down precipitation amounts by month. The box and whiskers plots show the distribution of precipitation each month, the blue or orange bars show this years values, and the plot on the right shows the percent of normal precipitation.
The following charts show cumulative annual precipitation. The first chart displays cumulative precipitation over the water year (Oct 1 - Sep 30), and the second chart shows Jan 1 to Dec 31. Total precipitation during the water year was very close to average; however, a very wet fall made the calendar year wetter than normal. 2024 was the sixth wettest year of the last 20 years at this weather station.
Atmospheric Rivers#
The chart below highlights significant atmospheric river (AR) events in 2024. The October 18-20 event was a 1:50 to 1:100 year event in some locations. Heaviest rains fell at the southern end of the water supply areas, and in the municipalities closest to the North Shore Mountains. In total, more than 10% of the total annual precipitation fell during this one event. Total rainfall during this AR event equaled average rainfall amounts for the month of October.
The image below shows the Capilano Reservoir immediately after the October 19-20 atmospheric river. Turbidity was very elevated, largely because there was a significant amount of shoreline exposed with the lake being low after the dry season.
